Support EU VAT Micro-business status

We're missing a schema entry for the new setting.

+  /**
+   * {@inheritdoc}
+   */
+  public function defaultConfiguration() {
+    return parent::defaultConfiguration() +
+      [
+        'digital_vat_enabled' => TRUE,
+      ];
+  }

Doesn't match the expected format. Example from the Custom tax type:

  /**
   * {@inheritdoc}
   */
  public function defaultConfiguration() {
    return [
      'display_label' => 'tax',
      'round' => TRUE,
      'rates' => [],
      'territories' => [],
    ] + parent::defaultConfiguration();
  }

+    $form['digital_vat_enabled'] = [
+      '#type' => 'checkbox',
+      '#title' => t('Collect VAT on digital products.'),
+      '#description' => t('Starting in 2019, the European Union introduced a €10,000 threshold for B2C (business-to-consumer) supplies of TBE (telecommunications, broadcasting, and electronic services). If you are under this threshold, uncheck this box. See <em>What changes on 1/1/2019</em> on the <a href="https://ec.europa.eu/taxation_customs/business/vat/telecommunications-broadcasting-electronic-services/content/when-and-where-charge-vat_en">European Union VAT for TBE website</a> for more details.'),
+      '#default_value' => $this->configuration['digital_vat_enabled'],
+    ];

The name of the checkbox is imprecise. It makes me think that if I uncheck it, no VAT will be collected. But that is untrue, unchecking the checkbox turns off the digital place of supply rules. We need to figure out a better label. Worth looking at how other systems label this setting, if they have it.

-    // Since january 1st 2015 all digital goods sold to EU customers
-    // must use the customer zone. For example, an ebook sold
+    // Since 1 January 2015, all digital goods sold to EU consumers
+    // must use the consumer's zone. For example, an e-book sold

Why was this changed? January 1st is the date format we use. And customer is more precise than consumer.

Here's the patch re-rolled on top of 2.15-dev.

I've made some small changes to address some of the issues above.

"We're missing a schema entry for the new setting": not fixed.
"public function defaultConfiguration() doesn't match the expected format": fixed.
"$form['digital_vat_enabled'] The name of the checkbox is imprecise": not fixed
"Since 1 January 2015. January 1st is the date format we use. And customer is more precise than consumer.": Fixed.

Some notes:

I think this is a good start but...

I think that this is a bit more complex than the patch suggests. The threshold is for B2C across EU borders. I suspect that if you have an organisation name in the address, then that's an indication that it's not B2C, and the threshold rule does not apply. I should have the opinion of an accountant soon.

Secondly, I think some products are inherently B2B - for instance a subscription for an organisation, so even if there's no VAT number, and no organisation name, they should be treated as B2B, which means that the MOSS threshold rules do not apply. In a module I built to handle the same problem a different way, I added two other configuration fields - one for apply_to_all_products and if that was not ticked a products field which listed products for matching against, being the B2B products.

Regarding 'digital_vat_enabled'. How about 'apply_moss_threshold_rule'?

The accountant made clear that their advice was not shareable, and my customer asked me not to share the advice. :-(

What I can say is that we are still using the patch, and I'm about to re-roll it.

Rerolled on top of 8.x-2.20. I've added some comments and mentioned MOSS in the UI with a link, so that it's clearer what this tick box is for.

Edit: the code here is correct, but the text I've added is incorrect. I am confusing the 10K limit and the MOSS scheme.

Actually, this issue is a little confused/confusing...

To use this patch you will need to be a taxable person (i.e. a business) based in the EU selling cross-border TBE services (telecommunications, broadcasting and electronic services) to non-taxable persons (i.e. consumers, not businesses). (All those words have technical definitions which you should check.) You should not use this if your business is based outside the EU, selling into the EU. Or if you do not have cross-border sales.

Normally sales made from one EU country to consumers in other EU countries are taxed at the rates of the countries in which the customers are located, and the tax charged is paid to the governments of those countries.

For TBE services specifically, there is an exemption which allows businesses with low cross-border turnovers to tax at the rate of their country, rather than at the rate of the consumer's country, with the tax being paid to the government of the country in which the seller is located. To be eligible to use this scheme the total turnover including VAT for cross-border TBE sales must be below EUR 10,000. (This is a high-level summary of the exemption - before taking advantage of this exemption, you should check the exact definitions and whether your business meets them.)

This patch allows Drupal Commerce to treat TBE products sold cross-border as subject to this exemption, calculating VAT at the rate of the seller's country.

It does not track the sales, to make sure that the store is below the threshold. It is the job of the administrator to switch this option on or off. It does not track whether sales in the previous calendar year were below the threshold (which is a requirement for taking advantage of the exemption); this too is the job of the administrator.

The patch does not deal with the MOSS scheme, which is a separate but related issue; EU companies selling cross-border TBE may register with the Mini One-Stop Shop (MOSS) service instead of registering with the tax authorities in all EU member countries, and then can pay the VAT they collected at one point rather than to all the individual countries. If you are using the exemption that the patch manages, then you would not normally be registered with your MOSS.

Companies outside the EU, selling TBE into the EU are required to register with MOSS and to charge and remit VAT. Such companies are not eligible for the exemption and should not use this patch.

The wording in the issue and help text in the last version of the patch, does not accurately reflect most of this.

Updating the issue description as the original has been superseded with #3216754: Prepare Commerce Tax for the EU July 2021 eCommerce VAT package.